Reinforcing-bar for concrete construction.



W. GOLDIE.

REINFORCING BAR FOR CONCRETE CONSTRUCTION.

APPLICATION FILED JULY 16.1917- 1 72,422. Patented July 10, 1918.

ATNT

WILLIAM GOLDIE, F WILKINSBURG, PENNSYLVANIA.

REINFORCING-BAR FOR CONCRETE CONSTRUCTION.

Specification of Letters Patent. Patented July 151%.,

t at 115.9110

Application filed July 16, 1917. Serial No. 18%,?68.

-ncw and useful Improvement in Reinforcing-Ba-rs for Concrete Construction; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relatesto reinforcing-bars for concrete construction, its object being to provide a strong and light bar having large exposure of surface to the concrete and providing means for anchoring the bar within the concrete in such way that the bar reinforces and anchors the concrete and the concrete reinforces and anchors the bar.

It comprises, enerally stated, a reinforcing-bar for concrete construction formed of a twisted I-shaped bani i. e. a bar having a central web portion with widened or thickened rib portions at each edge of the web. It also comprises other improvements as hereinafter set forth.

Figure 1 is a side view of a bar embodyin 'the invention; Fig. 2 is a cross-section of the same. Fig. 3 s a longitudinal central section of the same; Fig. 4 shows the bar embedded in the concrete; Fig. 5 a cross-section of the bar as so embedded; Fig. 6 a perspective view of the bar before twisting; Fig. 7 a like perspective view of a modified form thereof; and Fig. 8 a view of this modified form twisted to form the reinforcing-bar.

The reinforcing-bar 2 is,formed of any suitable structural shape having a central web portion,'for example, an I-bar, such as shown at 3, Fig.6, havin a web portion 4 and flange portions 5. This rolled bar is twisted either when hot or cold to. form the reinforcing-bar, such as illustrated in Fig. 1, in-

which case the web portion forms the spiral central portion 6, while the flanges provide spiral convolutions 7 extending around the same, so providing a bar of great strength and relative lightness, having pockets 8 for the reception of the concrete so that the concrcte maintains a strong hold upon the body of the bar. I

I prefer the structural bar of general I- shape because the flanges extend on opposite sides of the web, and so form a spiral depressed pocket for the reception of the concrete within the circumference of the spiral bar. Such construction gives pockets 8,

which extend under the ribs or flanges T! and form undercut pockets, and the concrete flows into these pockets and fills out under the ribs or flanges 7 and so under the eonvolutions of the flanges, so uniting the body of the concrete directly to the twisted bar.

The spiral tongue portions 9 of the concrete thus formed act as braces between the adjoining spirals of the bar and act to sustain the compression strains between the spiral Webs and flanges, filling the undercut pooliets 10 extending under the flanges 7, and the continuous spiral tongues 9 of concrete are thus bound within the twisted bar and in addition to anchoring the concrete to the bar, sustains all strains which might cause yielding of the bar itself. To this end, whiie I prefer that the corners of the flange portions 7 of the twisted bar shall be rounded, I preferthat the junction between the flanges and the web portion shall, if possible, be made angular, as illustrated, to better sustain the compression strains developed.

The twisted structural bar is made proportionately light as compared with a solid bar or a bar having a thick central portion. The thin web is braced spirally around its circumference by means of the flange portions and the twisted web 8,'plus the spirally-laid flange portions 7. giving a very strong, light structure adapted to resist strains in all (i rections,first, through the twisting of the web portion; and next, through the spiraliylaid flange portions. which, where the Web portion is approximately vertical, is adapted to sustain heavy loads, while-where the web is approximately horizontal, the spirallylaid flange portions are approximately vertical and are laid in such way as to sustain under tension from the highest and lowest parts of the bar all vertical strains and distribute them throughout the spiral flange portion of the structure. The reinforcing bar is thus adapted to sustain much heavier loads than the same, an'iount of metal in an. ordinary solid bar, and because of the greater diameter and surface exposure, it obtains a much stronger hold upon the concrete.

As illustrated in Fig. 4, the concrete itself by its spiral tongues fitting between two adjoining spiral flanges largely increases the strength of the beam or bar, sustaining the compression strain by reason of the concrete held between the same in the spiral recesses, as above described. The spirallyfad pression changes so gradually that where.

portions of the bar are under tension, other portions sustain it under such strain.-and where like portions are under compression. these strains are carried in the same way through the spiral lay both of the weband the flange portions. At the same time. the flanges extending over the pockets form practically dove-tailed seats, holding the concrete confined within. thenn where an I-shaped bar is used, and there is large exposure of the metal surface for holding of the concrete thereto.

Thus the reinforcing-bar provides in itself a spiral structure shaped to sustain and distribute the vertical or other strains coming upon the bar, and especially to sustain the tension strain while the filling of concrete provides a continuous spiral tongue fitting within the reinforcing-bar, firmly uniting the concrete to the bar and sustaining all compression strains brought upon the bar, so utilizing the concrete itself for bracing the spiral bar against compression strain. As shown in Figs. 1, 3 and 4, where the I bar has fiat outer faces, the twisting of the bar when cold provides the dislrshaped outer faces 12 following the surface of the spiral convolutions, and these depressed faces also act to hold the concrete in place.

In Figs. 7 and 8, I have. shown the beam with its web 15 and flanged heads 16 and central ribs 17 extending out beyond the heads.

The character of the twisted reinforcingbar formed from the bar is shown in Fig. 8 where the combined web ahd enlargements provide a very strong reinforcing structure. The shape and character of the flange or head portion, the thickness of the web etc. may, of course, be varied as found desirable. The invention is intended to cover any character of twistedmetal web structure having enlarged ends of flange or other form. l

. What I claim is:

1. A reinforcing-bar for concrete construction formed ofa twisted bar having aoutstanding flange sections beyond the ribportions, said flanges being of uniform section.

5. In reinforced concrete construction, the combination of a twisted bar having a sectional web portion and enlarged heads, and a. filling of concrete surrounding the beam and entering within the spiral pockets between the enlarged heads.

6. A reinforcing bar for concrete construction formed of a twisted bar having a central web portion and enlargements beyond the web, the web and enlargen'lents being connected by an angular joint. I

7. A reinforcing-bar for concrete construct'ion formed of a twisted I-shaped bar,

theouter faces of the convolutio-ns so pro duced being concave.

8. A reinforcing bar for concrete construction formed of a twisted bar having a central web portion and lateral extensions beyond the web.

9. A reinforcing 'bar for concrete construction formed of a twisted bar having a central web portion, and laterally extending edge portions.

In testimony whereof I the said VVILIJAM GoLoIn, have hereunto set my hand.

\NILLIAM GOLDIE.

iVitnesses James I. KAY, JOHN F. WILL. 

